Merck lambasted over semi-revelation

Drug touted as the potential 'successor' to Vioxx comes under the spotlight after trial results

An early glance at Merck's new data on the safety of its touted Vioxx replacement Arcoxia, upon which it will depend to secure marketing authorisation in the US, has revealed that while the drug is no more likely to cause thrombotic cardiovascular events than a popular product, it is associated with a greater number of blood pressure-related side effects.

However, scientists have criticised the beleaguered Merck for releasing insufficient data from its 34,000 patient MEDAL trial, in which both rheumatoid and osteo-arthritis sufferers were assessed, ruling out the possibility of drawing a definitive conclusion regarding its safety to patients.

The trial, which spread itself across 38 countries, saw Arcoxia (etoricoxib) pitted head to head against diclofenac, an older non-steroidal anti-inflammatory drug (NSAID) already widely prescribed in arthritis communities. Merck claimed that the product is the `most widely prescribed traditional NSAID in the world', and hence was an appropriate comparator for Arcoxia.

Results indicated that Arcoxia caused no more blood clot-related side effects than diclofenac, however treatment with Arcoxia was significantly more likely to result in patients pulling out of the trial due to `hypertension-related adverse events', Merck noted.

Also, people withdrawing due to oedema-related adverse effects was significantly higher than in diclofenac recipients, but was linked to the use of the highest dose (90mg) of Arcoxia. A significantly higher incidence of discontinuations due to gastrointestinal and hepatic side effects was also linked with this high dose, versus the 60mg level.

ìIt is up to physicians to monitor for these effects,î Reuters quoted Sean Curtis, head of arthritis clinical research for Merck.

While the data does not give Arcoxia a clean bill of health, even though it is already available in 62 countries including parts of Europe, Merck will rely on the data to get it through the Food and Drug Administration's (FDA) heightened regulatory scrutiny; already Merck has voluntarily withdrawn an earlier application for marketing approval, which on resubmission was not given the green light by the FDA.

The company, which is still achieving plenty of column inches in the world press as it struggles with the many thousands of pending law suits, has stated that it will release the new MEDAL data in its entirety through an as yet unnamed peer-reviewed medical journal, as well as at scientific meetings.

In the meantime, however, analysts and other onlookers can only surmise as to how positively, or not, the market will react towards Merck's replacement for Vioxx, which was pulled off the market two years ago due to evidence that prolonged use could cause heart attacks and strokes.

ìIt was a very carefully crafted press releaseÖ they didn't really release enough data for us to make a conclusion,î the New York Times heard from Dr Steve Nissen, who is overseeing a Pfizer-sponsored trial to assess Celebrex' heart risks.